1. Field
One or more embodiments of the present invention relate to a negative active material and a lithium battery including the same.
2. Description of the Related Art
Lithium secondary batteries have drawn attention for use as power sources for small portable electronic devices. Since lithium secondary batteries contain an organic electrolyte, they have a discharge voltage of at least twice that of general batteries containing an aqueous alkali electrolyte, and thus have higher energy density.
Lithium-transition metal oxides, such as LiCoO2, LiMn2O4, or LiNi1−xCOxO2 (0<x<1), having a structure allowing intercalation of lithium ions, may be used as positive active materials for lithium secondary batteries.
Research has been conducted on carbonaceous materials in various forms, such as artificial graphite, natural graphite and hard carbon, which allow intercalation and deintercalation of lithium ions. In addition, research has been conducted on non-carbonaceous materials such as silicon (Si), for use as negative active materials. Such non-carbonaceous materials exhibit a very high capacitance density that is at least ten times that of graphite. However, the cycle lifespan characteristics thereof deteriorate due to volumetric expansion and shrinkage of lithium during charging and discharging.